Tire casing and process of making the same



Dec. 28 1926.

J. -D. COMSTOCK TIRE casme AND PROCESS OF MAKING THE SAME I Filed Jun- 1924 3 Sheets-Shet 1 Dec. 28 ,1926. 1,611,998

V J. D. COMSTOCK TIRE CASING AND PROCESS OF MAKING THE SAME Filed June 1924 3 Sheets-Sheet 2 :9 TTOFA/ZCQS Dec. 28, 1926.

J 'DQCQMSTQ i'K U TIRE CASING AND PROCESS OFN'AMNGTRE SAME Filed June ,7 9 3 s heets sheet 5 30c i W v Thai-always Patented Dec. 28, 1926.

JAQKSOND. CGM'S'IIGGK; OF CE-IESTERyWEST -V1-RGINIA.1

TIREICASING ANB PROCESS OF IVIAKENGVVTHE SAME;

Applicat n:rfi c ifi nev2 2% al o '1- r This invention ,relatesqtopneumatic tires and. to a method of ftorming tire beads and carcasses.

it has heretofore been the pl'QViLlllngPIilQ- tice when constructing a tire casing tobuild" non-expansible. metalliorings. into the beads of the JCHG casinga-by securing-the annular edges-0t the fabric laminations constituting the, tire about these a single prings, thereby form ng a bead structure :WlllCll IS; substan:

tially nonexpansible radially. This is true and the result is that these outer laminationsl are subjected to vgreater str-ain. Also, regardless of how carefully: the-laminations are placed in position, certain laminations will usually be: tighter-than others, Ithas been observed, therefore, thatnndenthese circumstanceswhen; a itireis inflated one or a tow-ct the laminations.carry.most;ot the strain of the entire side wall and eventually;

become weakened or entirely give way, subsecuentl i tl11OWll1 ',-tl16 burden ;on; tov the other laminations. 1t -will :be seen vtheretore, othat it the-laminations are. evenly stretched, the liteof thetireuis inevitably.

greatly lengthened.

The-general object of the present inventiomtheret'ore is theprovision of noveltire construction.anda'suitableprocess tor build-c ing such a tire whereby each lamination comprising the-tire CttSHlgwlS so. formed at:

the head that"complete;adjustability may take place between-the tire ilamiiiations during the molding operation and. whereby each lamination mayso adapt-itself to itststressw environmentinithetlre structure that 1t may assume its full burden: of stress.

More specifically any invention; is directed vided with an individual metallic bead member adjusted inpthe finished. artioletoicause laminations of fabric whereby thecomposite.

bead structure may comprise individually sewrapped or cured edges of laminations, eachextending aroundone of several, convolutions of a con tinuous strand.- Thus, the bead edges of I each lamination. may be. of extreme vadaptability to variations inqtransverse lamination stresses 'andvariations in lamination width when the, composite head, is finallyformed; in the mold.

Other objects of my invention; will herein after beset torth intheiollowing deserip n lw ich ie i rs t thea compaying draw iii-gs illustratinga preferred method oi arr'in x. out the ets ot constructin altire 8i t:

casing; the lfll11l1 l l n$ of which v have individual beads, The -essential gcharaoteris; tics are summarized inthe claims lnlthe drawings Fig. 1 ,is aside elevatiom of a tire t'orm with one laminationapplied thereto, and illustratin the {beginning pf the application ot-asecond. lamination Fig. 2 is a diagramn' atic representation of the. tire form with tour laminationsapplied thereto: and illustrating V the manner of; forming ine dividual heads 1 for,; the laminations ,when; 1 using a continuousstrand of bead wire; Fig 3 is a fragmentaryperspective View L of: a

portion of the 013 11 and bead strrrotureot the carcass and two lamin at-ions of :the. tire carcass, illustrating the manner tot -progres s ng ztheib ad strandfromv one. lamination-11:0 another without interfering with-the individuality 0t? thebeadstructure Offiaqll lamination; F4 is a fragmentaryside-ele vation showing, the manner of splitting:thev laminations .to progress the strand tnomg one lamination to another; Fi 's; 5, 6 and? are. cross-sectional viewsillustrating the; proge rose of the strand from one.laminatioirto another; ;Fig. 8 is-a diagrammaticcross section of a tire casingwiththerl-ibber finishingstripsi inzassembled position upon the carcass; Fig. Q -is a cross-sectional viewot-a tire casing made in accordance-with this in vention illustratmgthe adaptability. of the v individualbead structure of eacho tabric lamination lnthe, casingwhe-n theaggrega-te 1s moldedinto a composite bead; Fig 'lO isa to the provisionof -attire structure wherein-H each lam1nation of the structure may be pros.

di'agram ot zthe .loops of the beadz:

A tire; in; which, the laminations are providedwith individual bead. structures whereby the-adaptation of thelaminations to. in ternal stressesis unopposed by the compos itebead. structure when the assembled casing is infiatedin the tire mold, mayhave twoor more laminations-as desired, the four lamination structure shown in the drawings beunit in a well known manner.

ing chosen merely for convenience in illustration. Briefly such a tire carcass may comprise, as shown in Fig. 8, four laminations or layers of tire cord, 12, 13, 1 1 and 15 and bead reinforcing or finishing fabric strips 16 and 17. Rubber finishing strips 20 complete the side wall structures and are overlapped by a tread strip 21 under which is placed the usual breaker strip 22. The cord lamii'istions 12 to 15 are assembled upon tire form and the individual beads for these strips comprise a composite bead when the tire is finally molded and cured.

A suitable form as shown in Figs. 1 and 2, may comprise a collapsible core 25 having removable wedge-shaped portions 26, the core being held together as a revolving The core 25 may be provided with flanges 27 which determine the bead diameter of the assembled carcass as will be hereinafter set forth. Any suitable means may be provided on the core for detachably securing free ends 31 of continuous bead strands 3O thereto. If desired, the bead finishing strips 16 and 17 may first be applied to the core 25 to overlie the side surfaces of the core and circumferential surfaces of the flanges 27. The free ends 31 of the strand may pass through small openings formed in the strips and into engagement with the core, preferably extending through openings formed in the core flanges. The first layer or inner lamination of cords 12 may then be applied to the core and be pressed or stitched to conform to the cross sectional contour of the form.

In Figs. 1 and 2 I have omitted the bead finishing strips 16 and 17 to more clearly illustrate the manner of continuing the bead strand from one lamination to another. As shown in Fig. 1 the first lamination has been completely applied to the form and the first convolution of the bead strand 30 has been applied thereto and the lamination edge 12 has been turned outwardly, to completely enclose the convolution 30" of the strand. The second lamination of fabric 13 is shown in Fig. 1 as being applied to the form over the first lamination with the cord strands thereof extending around the form at substantially 90 to the cords in the first lamination and the bead strands 30 are being simultaneously applied to the form. It is to be understood, however, that the lamination 13 could be applied to or completely pressed onto the form with the exception of the turned out portion 13", and then the continuation of the first convohr tion of the bead strand could be continued through a second convolution, in which case the second convolution 1 1 of the bead strand would be enclosed by turning outwardly the portion 13 of the second lamination.

When assembling the lamination upon the core shown in Fig. 1, the beginning of each subsequently applied lamination should be at the splice of the preceding lamination whereby the bead strands may continue from one lamination to another by extending through the respective splices of the laminations. As shown in Figs. 3 to 7 however, it is not essential that the strands extend from one lamination to another at this point, for each strand may extend through a slit formed in the outwardly turned portion 12 and through slit 13 in the turned out portion 13 of the second lamination 13. The slits are preferably spaced apart a sufficient distance that a short stretch of the cord strand may be disposed between the bead portions 12 and 13 as shown in Fig. 6 and whereby the progression of the bead strand from one lamination to the other may be uniform and without causing offsets or kinks in the strand.

It is to be understood that if desired, the bead strands may extend around the first lan'iination, say one and a fourth times before passing to the second lamination whence they extend around the second lamination one and a fourth times, etc., whereby the composite bead structure when finally formed in the mold may include five convolutions of head strand in each bead structure. Such an application of the bead strand would permit the assembling of the laminations with the splices thereof disposed sub stantially 90 apart.

The particular advantages of a tire casing made in accordance with my process will be readily apparent from the cross section of the tire casing shown in Fig. .9, the composite bead structure of which comprises a plurality of individual beads, one for each lamination of the carcass. It will be noted in this figure that the convolution 30 has expanded radially to a considerable distance away from the inner portion of the bead finishing strip 17 to which it originally was in the juxtaposed relation shown in Fig. 8. It will be also noted that the composite head to the right in Fig. 9 shows the bead strand convolution 30 as being substantially in its original assembled position while the convolution 30 has expanded considerably and is out of juxtaposition to the finishing strip 17. The condition illustrated is not exaggerated for this relative displacement of the bead is due primarily to the drawing or relative sliding of the laminations within the side walls of the tire whereby each lamination seeks to take its quota of stress and no more.

The variations in the expansion of the bead strand convolutions, is dependent upon the amount of inequality of stress load upon the laminations. The relative adjustment takes place when the tire is being expanded into the vulcanizing mold.

ll hen one loop or convolution is caused to expand, it contracts one or more of the adjacent loops until an even distribution of the strain has been effected. Such final relative position. of the loops is illustrated by th diagram of Fig. 10 in which the broken line 27 indicates the loop of an overwidth or loose lamination and the several loops of the other laminations are designated 30. When the vulcanizing is completed the finished tire has all of its several layers permanently adjusted and ready to equally resist the pressure of inflation. Tires made in accordance with this invention have shown remarkable wearing qualities and are capable of with standing very severe treatment.

I claim:

1. The method of forming a tire carcass which includes the steps of applying a lamination of fabricated cord to a tire form while applying a strand of bead forming material to the lamination adjacent each of its circumferential edges, turning said edges upwardly and outwardly whereby a convolution of each strand is completely enclosed by a turned edge of said lamination substantially joining the ends of the lamination, applying a second separate lamination to the first while engaging each circumferential edge thereof by a continuation of the respective strand engaging the first lamination and joining the ends of the second lamination, turning both edges thereof outwardly to enclose the second convolution of the strand and forming individual beads around the circumferential edges of subsequently applied laminations of material.

2. The method of constructing a tire casing which comprises placing a lamination of cord fabric material upon a tire forming core at each side of the carcass, applying a bead strand to the lamination adjacent its circumferential edge and substantially joining the ends of the lamination, applying a second lamination of material to overlie the first lamination and having its joining ends separated circumferentially of the tire relative to the ends of the first lamination and continuing the bead strand from the first lamination to the second lamination to form an individual bead therefor of substantially the same circumference and thus continuing the formation of individual beads of substantially the same circumference for each successive lamination applied to the form.

3. The method of forming tire carcass which includes the steps of applying separate laminations of fabricated cord to a tire form while applying a strand of bead forming material to the laminations adjacent each of the circumferential edges of each lamination, forming said edges outwardly whereby said strand is completeiy enclosed by the edges of said lamination, slitting said turned edges, applying the second lamination to the first while engaging the circumferential edges thereof by continuations of the strands extending from the first lamination through said slits, turning the edges thereof outwardly to enclose these second convolutions of strands and forming and slitting individual beads along the circumferential edges of sub sequently applied laminations of material whereby several convolutions of a continuous strand may form an individual bead for each fabric lamination.

4. A tire carcass comprising a plurality of laminations of fabric, each lamination be ing provided with a bead structure formed by a plurality of convolutions of a continuous bead strand, said bead strand passing through the material of the respective lamination to another.

In testimony whereof, I hereunto affix my signature.

JACKSON D. COMSTOCK. 

